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Obcom Protocol
Control and monitoring of professional audio equipment is rapidly becoming a necessity. Networking technology provides the vehicle that enables many advances in installation simplicity and system performance, from basic tuning and configuration of loudspeakers to complex array control and emergency evacuation system surveillance.

However, for a system of devices to participate in networked operation, each must talk a common 'language'. There has to be a unified way of describing actions which are to be performed. In the past, this has frequently been attempted by defining a 'remote control' protocol which described what commands were sent 'down the wires'. These commands would then each be individually decoded by the devices, and actions would be taken depending on the values in the command. It is now recognised that this is an inefficient, bug-prone and ineffectual way of doing things, and makes operation over different types of connection media difficult.

Our engineers carefully considered whether the world really needed yet another protocol. However, they decided that there was a strong requirement for a modern legacy-free object oriented approach that unified control and monitoring regardless of the means of transport. This protocol had to be suitable for both small and large systems and be easy to use for designers, installers and end-users alike.

Linea's response to the challenge is Obcom. Far more than just an equipment interfacing system - Obcom is a potent, yet low overhead messaging protocol whose tentacles reach deep inside each device, allowing an individual 'object' in a device to talk freely with any other object in the network as if the network and its cabling were not there. Importantly, Obcom is suitable for implementation not only on high performance platforms like PCs, but also runs effectively across slow networks and may be embedded inside devices that may not have much computing power such as wall mounted controllers.

Currently Linea Research supports Obcom over RS232, USB, 10mbs and 100mbs Ethernet (using TCP/IP - the Internet standard), and our own proprietary network solution, BvNET.

Under the Hood of Obcom
Obcom is a messaging technology developed by Linea Research specifically for controlling and monitoring professional audio products. Object Communicator (Obcom), is in essence a means by which an object (such as a control on a control panel) can communicate with any other object (such as a Parametric Equaliser) to facilitate control or monitoring. These two inter-communicating objects could be within the same device (such as an audio processing product), or in two different devices separated by some kind of interface or network.

Obcom is a clean, lightweight but powerful means for allowing devices to participate in a control and monitoring SYSTEM. Such a system allows devices to ‘speak’ the same language no matter what type of device and what type of parameter or what type of control. Obcom is highly organised, consistent and unified, avoiding ugly ‘special cases’.

Obcom is based on three disconcertingly simple principles:
1. Adjustable Parameters and the actions we wish to make on these are encapsulated in 'objects'
2. One object talks to any other object, using a standard message, regardless of its location or medium over which the message is routed
3. Parameter values are represented in a completely standardised form which NEVER changes

The central theme of Obcom is the Obcom Message, which describes in a very uniform way, what action is required. The format and contents of the message is exactly the same regardless of which type of device is used, or how the message is transported. Linea Research products use Obcom messages both internally and externally, so a message generated in a Windows PC computer may be sent via USB and end up being delivered to the display of an audio device in exactly the same format throughout. Indeed, the sending object does not need to know where the recipient object is, or how it is to be delivered. The messages will of course be 'packaged' in a way appropriate to the means of transmission.

For example, in a rack-mounting unit Obcom might be used to connect the main audio processing sub-system to its front panel control surface. As a result of using Obcom, the unit can be controlled locally by its control surface, or remotely via a network from multiple locations simultaneously. Obcom will keep each informed of the current state of the controlled object. This allows a PC and a wall panel to control the device just as easily as on the front panel of the device. When you adjust a control on the device, the corresponding controls on the PC and the wall panel will also change.. Immediately, and vice-versa.

Obcom is a closed protocol. That is, we do not publish its detail. Why would we do this? The reasons are very simple and very important. Obcom is not a simple ‘messaging’ protocol, it is deeply woven in to the software design of the product; it is not something that can be easily bolted on to products that were not originally designed to use it. The other common problem with standards is that people tend not to be interested in fully implementing the parts that they see no relevance in and hence don’t fully implement the standard, so it’s not a standard any more. We know exactly how Obcom is intended to work and we never break the rules, so we can guarantee that all devices are 100% compatible with one another. This makes the experience much simpler, more consistent, and more reliable for all concerned.

BvNET
Branch-able Versatile NETwork is (BvNET) is a physical layer networking standard created by Linea Research specifically for use in professional sound systems to allow audio devices to be monitored and controlled and to communicate with one-another, It is a straightforward, low cost communications medium that uses normal Cat5 cabling with RJ45 plugs. It does not require network equipment such as hubs. Products with BvNET interfaces use ruggedised Neutrik locking RJ45 connections which are also compatible with standard RJ45 connectors. Connections may be freely branched, giving complete freedom of connection topology such as daisy-chain, star, ring, tree etc. Unlike other network types there is no restriction on the cabling span length between devices, although the maximum total length of cabling between devices at the extremities of the network may not exceed 3200 feet (1000 metres). Even this can be extended using repeaters. There is also no need to worry about terminating the ends of the networks as for example is required with DMX. Up to 119 devices may participate in a BvNET network. It is a true peer-to-peer network, meaning that there is no concept of a Master - any device can communicate with any other device on the network on an equal standing. The installer doesn't have to worry about setting unique addresses for the devices on the network - this is all taken care of automatically.
The Linea Research BvNET Interface allows a computer access to a BvNET network via either RS232 serial or USB.